Oral hygiene device

ABSTRACT

A hydraulic oral hygiene structure which produces a pulsed stream of water without employing a pump or other motor driven reciprocating device. The structure includes an elongated handle having an opening therein which leads to a race chamber which may enclose a spherical ball which is rotatable over a circular path or paths within the race chamber. A plurality of apertured nozzles are affixed to the race chamber and they are so arranged that, as the ball revolves within the chamber, water flowing through the race chamber will be emitted through the apertures of the nozzles in a pulsed stream or streams. The nozzles are tapered and flexible so that their ends may be moved between the teeth or against the gums or both.

United States Patent Parkison lane 5, 1973 541 ORAL HYGIENE DEVICE 2,595,491 5 1952 Schweikert ..l28/66 ux [75] Inventor: Richard Grant Parkison, Louisville, 1,848,621 3/1932 Gollwitzer ..l28/62 A Primary Examiner-Lawrence W. Trapp [73] Assignee: American Standard Inc., New York, y- Ehrlich N.Y. [57] ABSTRACT [22] Filed: Jan. 4, 1971 A hydraulic oral hygiene structure which produces a PP N04 103,463 pulsed stream of water without employing a pump or other motor driven reciprocating device. The struc- 52 u.s. Cl ..l28/66 includes an elongated handle havin an Opening [51] Int. Cl. ..A61h 9/00 herein which each h chamber which h [58] Field of Search ..l28/62 A 66 65 a sphercal Mable a 128/67: 1 path or paths within the race chamber. A plurality of apertured nozzles are affixed to the race chamber and they are so arran ed that, as the ball revolves within [56] References cued the chamber, wat r flowing through the race chamber UNITED STATES PATENTS will be emitted through the apertures of the nozzles in a pulsed stream or streams. The nozzles are tapered l,327,757 1/1920 Eggers ..40l/28 and flexible so that their ends may be moved between FOX i the teeth or against the gums or 3,500,824 3/1970 Gilbert ..l28/62 A 2,081,792 5/1937 Cassanos ..128/62 A 18 Claims, 9 Drawing Figures I a f Iii PATENTEDJun 5197s SHEET 10F 3 uw 0L0 um RICHARD G. PARKISON INVENTOR ATTORNEY PATENTEUJUN 5 I975 3,736,923

SHEET ZUF 3 F l G .7

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F I G 5 HNO4 PS RC RlCHA G. RKISON IN NT ATTORNEY PATENTEUJUN 51975 3.736.923 SHEET 30F 3 RICHARD e. PARKISON INVENTOR.

BY E

ATTORNEY ORAL HYGIENE DEVICE This invention relates to hydraulic oral hygiene structures for producing pulsed streams of water for cleansing the mouth and, more particularly, for dislodging food particles between the teeth and for massaging the gums. More particularly, this invention relates to such hydraulic oral hygiene structures which do not employ a pump or other motor driven reciprocating apparatus for generating one or more pulsed streams for the cleansing operation.

Conventional hydraulic oral hygiene apparatus usually includes a motor driven pump or other reciprocating device for deriving from a substantially continuous stream of pressurized water delivered from a lavatory faucet a pulsed single stream of water to perform the hygienic services. Such a pulsed single stream of water may be especially useful, not only for cleansing the teeth and the spaces between the teeth, but also for stimulating the gums of the mouth. Such conventional equipment customarily employs a form of mechanical switch, a water tank, and additional bulky equipment for starting and stopping the motor and pump operation so as to build up the flow conditions. Such a complex network of equipment necessarily becomes quite expensive not only in its first cost but also in the maintenance and operation of the apparatus. Because of the cost factors and the complexity and maintenance problems inherent in the use of suchapparatus, and the necessity for filling a water tank and then removing all of the unused water and for drying the equipment after each use, there has been obvious resistance to widespread use of such apparatus. Moreover, many of those who have used such equipment have been dissatisfied with its operation due to breakdowns, replacements of parts, delays in repairs, etc.

According to the present invention, a simple hydraulic oral hygiene device has been devised for continuously producing one or more pulsating or oscillating streams of water which are derived or tapped from an ordinary faucet or other source of water without the employment of a pump or other motor driven reciprocating apparatus or a water storage tank or other bulky apparatus. The device of this invention includes an elongated handle having a longitudinal opening therein which leads to a relatively small cylindrical race chamber housing enclosing one or more spherical balls which are driven in continuous circular paths around the periphery of the race chamber. The housing also embodies or embraces a plurality of flexible nozzles which are finely apertured and the nozzles and their respective apertures may be equally spaced within the orbit of the race chamber. Moreover, the exposed ends of the nozzles may be tapered or pointed. Hence, water under normal city pressure travelling through the opening of the slender elongated handle will tangentially enter the race chamber and drive the ball or balls therein in circular paths which are traversed again and again so that the ball or balls will regularly open and close the apertures of the nozzles, or partially open and close the apertures, thereby to generate pulsed streams as the water is exited from the apertured nozzles. Hence, by inserting the nozzle structure of the device into the mouth, the user may easily direct the streams of pulsating water for driving foreign matter away from the teeth and from the spaces between the teeth, and the streams may also be pulsatingly driven against the gums to produce hammer-like blows against the gums for their exercise and stimulation. Moreover, the ends of the nozzles may be tapered or pointed and flexible, if so desired, so that they may be moved by the user between the teeth or against the gums while pulsating water is being delivered to the same locations.

The structure of the present invention is completely free of any electrical equipment. No electrical motor or motor driven pump or other reciprocating structure is employed or required in the operation of the device of this invention. No water storage tank is employed. No complex switching or other equipment is required. The structure is simple, easy to manufacture, easy to use, low in cost and substantially free of the various problems that usually accompany conventional motor driven pumping equipment employed in hydraulic oral hygiene apparatus.

This invention will be better and more clearly understood from the more detailed description and explanation hereinafter following when read in connection with the accompanying drawing which is directed to exemplify one form of equipment suitable for the practice of the invention.

In the drawing:

FIG. 1 illustrates a side view, partly in section, of one form of elongated multiple nozzle device according to this invention, in which the nozzles are shown pointed in a downward direction;

FIG. 2 illustrates a longitudinal cross-sectional view of the device of this invention when viewed along the lines BB of FIG. 1;

FIG. 3 shows a partial bottom plan view when looking at the nozzle ends illustrated in FIG. 1;

FIG. 4 shows a simple cross-sectional view of the handle of the device of this invention when viewed along the line C-C of FIG. 2;

FIG. 5 shows an enlarged partial cross-sectional view of the raceway segment of the handle structure as the main individual component of the arrangement employed in this invention;

FIG. 6 shows a partial top plan view of the raceway segment of the handle component shown in FIG. 5;

FIG. 7 shows a cross-sectional view of the cap for the raceway segment of the handle shown in FIGS. 5 and FIG. 8 shows a cross-sectional view of one form of apertured nozzle which may be employed in the practice of this invention; and

FIG. 9 illustrates schematically a form of plumbing connection for joining the device to a faucet of a lavatory or other plumbing fixture.

Referring to the drawing, and especially to FIGS. 1 and 2 of the drawing, there is shown a slender, elongated handle HN which has a longitudinal central channel or opening or openings which lead to a race chamber RC which is preferably formed integrally with the handle HN. The handle HN has a main opening l-INOI through which water is allowed to enter the main channel or opening or openings of the handle HN. As will be clearly understood, the main opening HNOI may readily accept a conventional threaded flexible hose for connection to the faucet of a lavatory or other source of water supplied under usual city pressure. The flexible hose may be threadedly connected to the internally threaded segment TH of the handle HN. A form of assembled structure is illustrated in FIG. 9 in connection with the faucet of a lavatory.

The main opening HNtll leads to sequential openings HNOZ, HN03 and HNtM which may be co-linear with each other. They may have the same internai diameters but preferably have different diameters, the diameters being reduced in the downstream direction as shown, for example, in FlG. 2;. By reducing the internal channel diameters in the downstream direction, the water velocity within the inner passage of the handle HN will be progressively and correspondingly increased as the water approaches the race chamber RC.

The water leaving channel HNti t may then enter an off-normal passage PS leading to the raceway chamber RC. The passage PS is in line with a plug PG. The passage PS will cause the incoming water to be directed tangentially into the raceway RC. The cap CP is affixed to the raceway chamber RC by means of a threaded screw SC to completely house the race chamber RC. The shank of the screw SC provides a convenient center post for aiding and guiding the incoming water and maintaining the incoming water in a predetermined tangential path upon entrance and cause it to travel in a continuous path which may be circular or elliptical. The water will therefore flow in a substantially continuous stream around the threaded shank segment of the screw SC and the path of the water will be in a direction which, when viewed from FIG. 2, will be clockwise within the chamber RC.

A ball BL (or several balls BL), preferably spherical in shape, may be retained within the race chamber RC. When at rest due to the absence of water in motion in the race chamber, a ball, such as BL, may be seated on a particular nozzle NZ which has a central, rather narrow aperture NZA, as is more clearly shown in FIGS. 1 and 8. When in this position, little or no water will travel through the nozzle NZ upon which the ball is seated. However when the ball is driven along its circular or elliptical path under the influence of the water in motion within the raceway RC, the ball BL will travel in its circuitous path throughout the raceway RC and, from time to time, fully or partially block the apertures of all nozzles retained by the raceway chamber. This will create the pulsating or undulating streams derived from the several nozzles.

FIGS. 5 and 6 illustrate a portion of the handle structure which may be a single plastic casting or component having a threaded segment CPT for receiving and retaining the threaded screw SC or a center-post. The handle HN may be made of any form of material, preferably celcon or any other appropriate plastic material. The handle HN is shown to embrace a plurality of spaces for receiving and holding all of the nozzles such as NZ. Each nozzle NZ is preferably made of a flexible material, such as silicone rubber. Each nozzle NZ is preferably tapered or double tapered as shown, for example, in FIG. 8, and its end is preferably pointed. For example, the end of each nozzle NZ may taper to a diameter of about 0.025 inch or less. Such a narrow termination for the nozzle NZ will be especially useful in moving the end of the nozzle into the confined spaces between the teeth. Moreover, the contour of the nozzle NZ is formed into a collared channel NZC (see FIG. 8) so that the nozzle NZ may be easily held by the inner wall NZW (see FIG. 5) notwithstanding the pressures to which the nozzle may be subjected. Hence, all of the nozzles NZ will be substantially fixed in position within the raceway chamber RC. Each nozzle may be easily removed whenever desired for replacement or other purposes.

Each nozzle is sufficiently long and slender and therefore sufficiently flexible so that its end or terminus may be bent over a considerable arc by relatively light physical pressure applied by the user against the teeth or gums. For example, a nozzle NZ may be about 4/10 inch long and the nozzle NZ may be readily flexed perhaps over an arc of about inch or even more. By pro viding a sufficiently long nozzle of appropriate flexibility (for example, by using material of between 50 and 60 durometers), the flexure of the nozzle NZ may be made as large as may be desired under the prevailing conditions encountered in actual practice.

An tb-ring OR may be positioned between the cap CP and the handle HN, as shown in FIG. 2, for improving the seal of the handle HN to block any leakage of water out of the handle HN and its race chamber RC while water is being conveyed by the device.

If the device is connected to a water source that has excessive pressure, the flexible nozzles NZ act as flow regulating devices to limit the velocity of the streams that exit from the nozzle tips so as not to be damaging or harmful to the users mouth. When the water pressure becomes excessive, this pressure is exerted upon the top portion NZT of each nozzle that is contained within the counter-bore NZB. This pressure on the top of the nozzles causes the rubber to be compressed and the aperture NZA to be reduced at the upper or upstream portion of the nozzle. This limits the flow through the aperture NZA and thereby limits the velocity of the water exiting from the tip of the nozzle. The flexible nozzle NZ therefore acts like a flow regulator to render substantially constant the flow through the nozzle under changing water pressure conditions.

In the operation of the device according to this invention, water flowing through the passage HNfll, HN02, HNOS and HNtM will drive the ball BL in a recurrent circular path about the centerpost established by the screw SC. The ball BL will momentarily close or partially close the aperture NZA of nozzle NZ as the ball momentarily passes the aperture. The flow of water will thus be periodically interrupted or otherwise modulated to establish oscillating or pulsating water forces. The employment of two balls BL will double the frequency of the pulsating streams, three balls will triple the frequency of the pulsating streams, and so on. The multiple stream production may improve the operating efficiency of the device for cleaning teeth, stimulating the adjacent gums at the same time, and for other oral service.

While the raceway chamber RC is shown as embracing six apertured nozzles, it will be apparent that the raceway chamber may be devised and organized for accommodating any desired number of nozzles, whether or not more or less than six, all preferably spaced equidistantly from each other, but any other spacing will suffice. While one ball BL may be sufficient for the practice of this invention, the employment of two or more balls will'produce pulsating streams of increased frequencies thereby improving the efficiency and effectiveness of the device. Any arrangement employing two or more balls should preferably involve plastic materials for the ball composition.

The ball or balls BL may be omitted from the composite structure, if desired. In that case, a plurality of non-oscillatory streams will be generated and will be useful in oral hygiene service.

Whenever the balls BL are to be removed and whenever one or more nozzles NZ are to be removed, it is only necessary to unscrew the threaded device SC. After the balls or nozzles are replaced, a few turns of the device SC will be sufficient to re-seal and reconstitute the structure.

FIG. 9 shows a conventional lavatory LV provided with a conventional faucet FC and a spout end SE1. The spout end SEll is shown as embodying a branch BR leading to another spout end SE2 which has a conventional threaded section for receiving one end EN] of a coupler CPI to which a flexible hose Fl-i is connected in any well known manner. The flexible hose FH is provided with a second coupler CP2 which is provided with an externally threaded member which is to be joined to the internally threaded section TH of the handle HN (see FIG. 2). The coupler CPI may be connected to the spout end SE2 whenever oral hygiene service is desired and may be disconnected whenever such service is to be terminated. Any selector valve or diverter valve, such as is schematically designated SL, may be associated with or incorporated in the branch BR for regulating the water flow in any well known manner, to have the water exit through spout end SE2, or through coupler CPI and through hose Fl-l to handle HN and nozzles NZ, or to regulate the volume and temperature of the water flow in either path.

On the other hand, any form of valve mechanism (not shown) may be inserted between the spout end SE1 and the coupler CP2 for opening or closing the fluid path to the handle HN. Thus, by manipulating the valve mechanism, oral hygiene service may be initiated or terminated as may be desired. Any other form of coupling mechanism may be substituted for the arrangements shown in FIG. 9 for fluidically interconnecting the handle HN to any spout end or to the faucet to which the spout end may be affixed.

While this invention has been shown and described in certain particular arrangements merely for illustration and explanation, it will be readily apparent and understood that the arrangement of this invention may be embodied in many and varied forms suitable to carry out the principles of this invention.

What is claimed is:

1. Hydraulic oral hygiene apparatus for a water outlet, comprising a curvilinear continuous raceway having one opening for incoming water and another opening for retaining a nozzle, a spherical roller within said raceway which is movable in response to the incoming water to move along said raceway to modulate the water travelling through the aperture of said nozzle so as to pulsate the water flowing therethrough.

2. Hydraulic oral hygiene apparatus according to claim 1, in which the raceway is substantially cylindrical so that the spherical roller will move through a substantially circular path.

3. Hydraulic oral apparatus according to claim 2, including one or more additional nozzles all of which are spaced at predetermined distances from each other so that the spherical roller will sequentially close, partially or completely, the openings of all of the nozzles as it traverses said raceway.

4,. Hydraulic oral hygiene apparatus according to claim 1, in which the nozzle is made of flexible material and is tapered into a very narrow terminus so that the substantially narrow terminus of said nozzle may be flexed over a substantially wide angle.

5. Hydraulic oral hygiene apparatus for a water outlet, comprising a circularly cylindrical raceway housing having a substantially central post, a first port in said housing for receiving incoming water which is to travel in a circular path over said raceway housing, a second port for said raceway housing, a flexible apertured nozzle retained within the second port of said housing, and a spherical roller responding to the pressure of incoming water to periodically and substantially continuously modulate the water flowing through the aperture of said nozzle.

6. Hydraulic oral hygiene apparatus according to claim 5, in which the first port is shaped so as to transmit incoming water tangentially into the raceway housing.

'7. Apparatus according to claim 5 comprising, instead of one nozzle, a plurality of nozzles which are spaced at predetermined distances from each other so that, as said roller travels along the raceway of said housing, it will sequentially and substantially modulate the flow of water through the apertures of said nozzles to produce a plurality of pulsating streams of water.

8. Apparatus according to claim 7, in which each nozzle is made of a rubberized material and tapered to a relatively small dimension so that the end of each nozzle may be flexed through substantially wide angles in response to relatively small manual pressure.

9. Apparatus according to claim '7, in which the raceway housing is integrated with an elongated handle having a longitudinal bore through which water is received and re-transmitted tangentially to the raceway housing.

10. Hydraulic oral hygiene apparatus comprising an elongated handle having a longitudinal bore through which water is to be transmitted, a circularly cylindrical raceway housing coupled to the handle so that the water transmitted through the bore of the handle will enter the raceway housing, a center-post within said raceway housing for guiding the flow of water therein, a plurality of rollers positioned within the raceway housing and movable in response to incoming water and travelling over the circular path of said raceway housing, and a plurality of apertured nozzles coupled to the raceway housing, said rollers travelling sequentially over all of the nozzles so as to regularly modulate the flow of water through each of said nozzles.

11.. Apparatus according to claim it), in which the top end of each nozzle is flexible and changes in shape in response to the pressure of the water travelling into the raceway housing to maintain the water flow through the nozzle substantially constant.

K2. Apparatus according to claim 10, in which each of the apertured nozzles is made of a flexible or rubberized material and is tapered so that the end of the nozzle downstream of the raceway housing is relatively small and may be widely flexed in response to relatively small manual pressure.

13. Hydraulic oral hygiene apparatus comprising a housing made of substantially inflexible material, a plurality of miniaturized apertured parallel nozzles mounted within said housing so that a segment of each nozzle is exposed beyond said housing, each nozzle being made of flexible or rubberized material and tapered to a relatively small terminus so that pressurized water entering the housing will be delivered simultaneously to the apertures of all of said nozzles and exited through the termini of all of said nozzles and so that each terminus may be flexed while said pressurized water is being delivered through the apertures of said nozzles, and a spherical ball freely mounted within the housing and freely movable in response to the flow of water into said housing for modulating the streams of water ejected by said nozzles.

14. Oral hygiene apparatus according to claim 13, including an elongated handle which is integrated with said housing for guiding the movement of the housing within a users mouth.

15. Hydraulic oral hygiene apparatus comprising a nozzle made of rubber-like material having a substantially broad upstream surface and a tapered body having a substantially pointed downstream terminus and a narrow longitudinal aperture extending throughout said body, a housing within which the broad upstream surface of said nozzle is mounted, and a movable body positioned within said housing and responding to the fluid traversing said housing to vary the fluid pressure applied to the upstream surface of said nozzle, said upstream surface of said nozzle responding to pressure changes in the fluid impinging on the upstream surface of the nozzle to change the size of the upstream end of the aperture and thereby regulate the quantity of fluid flowing through the aperture, said downstream terminus being flexible over an angle corresponding to the manual pressure applied to the nozzle.

16. Oral hygiene apparatus according to claim 15, in which the longitudinal aperture is substantially uniform in cross-section and extends from the broad upstream surface to the downstream terminus.

17. Hydraulic oral hygiene apparatus for producing a modulated stream of water comprising an elongated handle having a longitudinal bore for receiving water therethrough, a nozzle having a tapered apertured body and having a rubber-like terminus, and means including a continuous flow path in said nozzle for fluidically coupling said handle to said nozzle, said coupling means including a roller which is movable over said continuous flow path for substantially periodically modulating the water flow through said nozzle.

18. Oral hygiene apparatus according to claim 17, in which the continuous flow path is in the form of a substantially oval raceway providing a track for the roller thereby providing a continuous path over which the roller is movable. 

1. Hydraulic oral hygiene apparatus for a water outlet, comprising a curvilinear continuous raceway having one opening for incoming water and another opening for retaining a nozzle, a spherical roller within said raceway which is movable in response to the incoming water to move along said raceway to modulate the water travelling through the aperture of said nozzle so as to pulsate the water flowing therethrough.
 2. Hydraulic oral hygiene apparatus according to claim 1, in which the raceway is substantially cylindrical so that the spherical roller will move through a substantially circular path.
 3. Hydraulic oral apparatus according to claim 2, including one or more additional nozzles all of which are spaced at predetermined distances from each other so that the spherical roller will sequentially close, partially or completely, the openings of all of the nozzles as it traverses said raceway.
 4. Hydraulic oral hygiene apparatus according to claim 1, in which the nozzle is made of flexible material and is tapered into a very narrow terminus so that the substantially narrow terminus of said nozzle may be flexed over a substantially wide angle.
 5. Hydraulic oral hygiene apparatus for a water outlet, comprising a circularly cylindrical raceway housing having a substantially central post, a first port in said housing for receiving incoming water which is to travel in a circular path over said raceway housing, a second port for said raceway housing, a flexible apertured nozzle retained within the second port of said housing, and a spherical roller responding to the pressure of incoming water to periodically and substantially continuously modulate the water flowing through the aperture of said nozzle.
 6. Hydraulic oral hygiene apparatus according to claim 5, in which the first port is shaped so as to transmit incoming water tangentially into the raceway housing.
 7. Apparatus according to claim 5 comprising, instead of one nozzle, a plurality of nozzles which are spaced at predetermined distances from each other so that, as said roller travels along the raceway of said housing, it will sequentially and substantially modulate the flow of water through the apertures of said nozzles to produce a plurality of pulsating streams of water.
 8. Apparatus according to claim 7, in which each nozzle is made of a rubberized material and tapered to a relatively small dimension so that the end of each nozzle may be flexed through substantially wide angles in response to relatively small manual pressure.
 9. Apparatus according to claim 7, in which the raceway housing is inteGrated with an elongated handle having a longitudinal bore through which water is received and re-transmitted tangentially to the raceway housing.
 10. Hydraulic oral hygiene apparatus comprising an elongated handle having a longitudinal bore through which water is to be transmitted, a circularly cylindrical raceway housing coupled to the handle so that the water transmitted through the bore of the handle will enter the raceway housing, a center-post within said raceway housing for guiding the flow of water therein, a plurality of rollers positioned within the raceway housing and movable in response to incoming water and travelling over the circular path of said raceway housing, and a plurality of apertured nozzles coupled to the raceway housing, said rollers travelling sequentially over all of the nozzles so as to regularly modulate the flow of water through each of said nozzles.
 11. Apparatus according to claim 10, in which the top end of each nozzle is flexible and changes in shape in response to the pressure of the water travelling into the raceway housing to maintain the water flow through the nozzle substantially constant.
 12. Apparatus according to claim 10, in which each of the apertured nozzles is made of a flexible or rubberized material and is tapered so that the end of the nozzle downstream of the raceway housing is relatively small and may be widely flexed in response to relatively small manual pressure.
 13. Hydraulic oral hygiene apparatus comprising a housing made of substantially inflexible material, a plurality of miniaturized apertured parallel nozzles mounted within said housing so that a segment of each nozzle is exposed beyond said housing, each nozzle being made of flexible or rubberized material and tapered to a relatively small terminus so that pressurized water entering the housing will be delivered simultaneously to the apertures of all of said nozzles and exited through the termini of all of said nozzles and so that each terminus may be flexed while said pressurized water is being delivered through the apertures of said nozzles, and a spherical ball freely mounted within the housing and freely movable in response to the flow of water into said housing for modulating the streams of water ejected by said nozzles.
 14. Oral hygiene apparatus according to claim 13, including an elongated handle which is integrated with said housing for guiding the movement of the housing within a user''s mouth.
 15. Hydraulic oral hygiene apparatus comprising a nozzle made of rubber-like material having a substantially broad upstream surface and a tapered body having a substantially pointed downstream terminus and a narrow longitudinal aperture extending throughout said body, a housing within which the broad upstream surface of said nozzle is mounted, and a movable body positioned within said housing and responding to the fluid traversing said housing to vary the fluid pressure applied to the upstream surface of said nozzle, said upstream surface of said nozzle responding to pressure changes in the fluid impinging on the upstream surface of the nozzle to change the size of the upstream end of the aperture and thereby regulate the quantity of fluid flowing through the aperture, said downstream terminus being flexible over an angle corresponding to the manual pressure applied to the nozzle.
 16. Oral hygiene apparatus according to claim 15, in which the longitudinal aperture is substantially uniform in cross-section and extends from the broad upstream surface to the downstream terminus.
 17. Hydraulic oral hygiene apparatus for producing a modulated stream of water comprising an elongated handle having a longitudinal bore for receiving water therethrough, a nozzle having a tapered apertured body and having a rubber-like terminus, and means including a continuous flow path in said nozzle for fluidically coupling said handle to said nozzle, said coupling means including a roller which is movable over said continuous flow path for substantially pEriodically modulating the water flow through said nozzle.
 18. Oral hygiene apparatus according to claim 17, in which the continuous flow path is in the form of a substantially oval raceway providing a track for the roller thereby providing a continuous path over which the roller is movable. 